Diaphragm valves are a type of flow control device. Existing diaphragm valves include a valve body and a dome shaped diaphragm. A seal is provided between the diaphragm and the valve body at or near the outer peripheral area of the diaphragm. A bonnet may be used to clamp the diaphragm to the valve body to provide the seal between the valve body and the diaphragm. In order to achieve a satisfactory seal, high compressive forces may be needed, especially where imperfections in the valve body and diaphragm surfaces exist and where the diaphragm is made of harder materials.
The valve body typically includes a passageway between the inlet and the outlet of the valve. An actuator is typically employed to flex the diaphragm into engagement with a valve seat to seal off the passageway when desired. Forming a satisfactory seal between the diaphragm and valve seat is important to the performance of the valve.